Book Image

Hands-On Design Patterns with C++

By : Fedor G. Pikus
Book Image

Hands-On Design Patterns with C++

By: Fedor G. Pikus

Overview of this book

C++ is a general-purpose programming language designed with the goals of efficiency, performance, and flexibility in mind. Design patterns are commonly accepted solutions to well-recognized design problems. In essence, they are a library of reusable components, only for software architecture, and not for a concrete implementation. The focus of this book is on the design patterns that naturally lend themselves to the needs of a C++ programmer, and on the patterns that uniquely benefit from the features of C++, in particular, the generic programming. Armed with the knowledge of these patterns, you will spend less time searching for a solution to a common problem and be familiar with the solutions developed from experience, as well as their advantages and drawbacks. The other use of design patterns is as a concise and an efficient way to communicate. A pattern is a familiar and instantly recognizable solution to specific problem; through its use, sometimes with a single line of code, we can convey a considerable amount of information. The code conveys: "This is the problem we are facing, these are additional considerations that are most important in our case; hence, the following well-known solution was chosen." By the end of this book, you will have gained a comprehensive understanding of design patterns to create robust, reusable, and maintainable code.
Table of Contents (21 chapters)

Summary

In this chapter, we have studied, in detail, one of the best C++ patterns for writing exception-safe and error-safe code. The ScopeGuard pattern allows us to schedule an arbitrary action, a fragment of C++ code, to be executed upon completion of a scope. The scope may be a function, the body of a loop, or just a scope inserted into the program to manage the lifetime of local variables. The actions that are executed to the end may be conditional on the successful completion of the scope, however that is defined. The ScopeGuard pattern works equally well when success or failure are indicated by return codes or exceptions, although in the latter case we can automatically detect the failure (with return codes, the programmer has to explicitly specify which return values mean success and which do not). We have observed the evolution of the ScopeGuard pattern as more recent...